Eggs: Cholesterol Confusion

Don't let cholesterol confusion scramble your diet.

Culinary Medicine

by Mary B Grosvenor, MS, RD and

Lori A Smolin, PhD 

In 1953, researcher Ancel Keys hypothesized that high intakes of saturated fat and cholesterol raised blood cholesterol levels, which contributed to cholesterol buildup in the artery walls, a condition known as atherosclerosis.[1,2] As a result of his studies, in the 1960s the American Heart Association began to recommend limiting our cholesterol intake to no more than 300 mg/day to reduce the risk of heart disease.[3]

Eggs were a focus of these recommendations because one egg contains about 200 mg of cholesterol, more than any other individual food. This recommendation held for over 50 years until newer data challenged the restrictions on cholesterol and eggs.[4,5] After years of avoiding them, many of us are wondering how eggs, and the cholesterol they contain, fit into a healthy diet. 

The Nutritional Benefits of Eggs

Eggs are nutrient dense, meaning they are high in nutrients relative to the number of calories they provide.[6]  An average chicken egg has 70 Calories, 7 grams of protein, less than a gram of carbohydrate, and about 5 grams of fat, most of which is healthy poly- or monounsaturated fat. The high-quality, readily digestible protein in eggs makes them a valuable protein source; they have been shown to reduce malnutrition in children in developing countries and to support the protein needs of athletes trying to build muscle and of older adults trying to prevent muscle loss.[7] The high-protein, low-carbohydrate profile of eggs also makes them more filling than foods higher in carbohydrate. Eating eggs for breakfast has been shown to increase satiety, helping maintain a calorie deficit throughout the day and therefore supporting weight loss.[7,8] Although eggs are high in cholesterol, unlike other sources of cholesterol, such as fatty meats and full-fat dairy products, eggs are not high in saturated fat. 

Eggs are a source of the fat-soluble vitamins A, D, E, and K; the B vitamins folate and vitamin B₁₂; and the minerals zinc, iron, and selenium. Eggs are also a primary source of choline in the US diet. Choline, although not a vitamin, is needed to form cell membranes and support brain and nervous system function. Diets high in choline have been associated with a lower risk of cardiovascular disease, especially stroke.[9] The golden color of the egg yolk is due to the carotenoids, lutein, and zeaxanthin, which have antioxidant and anti-inflammatory properties. Lutein and zeaxanthin have been found to help prevent the eye diseases macular degeneration and cataracts; they may also reduce cognitive decline in older adults.[10]

Clarifying Cholesterol 

The cholesterol in our bodies comes from what we consume in food and from cholesterol synthesized by our liver. Dietary cholesterol is only found in food from animal sources such as eggs, meat, and dairy products. So, if you eat a vegan diet, and thus do not eat any cholesterol, your liver will make all you need. 

Cholesterol is used by the body to synthesize steroid hormones, such as estrogen, testosterone, and cortisol. It is also needed to form cell membranes; it is particularly important in brain and other nervous tissue where it is a component of myelin, an insulating layer around nerve cells. Cholesterol circulates in the blood in several types of transport particles, including LDLs (low-density lipoproteins), which carry cholesterol from the liver to cells throughout the body, and HDLs (high-density lipoproteins), which carry cholesterol back to the liver for elimination from the body. Elevated levels of LDL cholesterol can lead to plaque buildup in artery walls, restricting blood flow and increasing the risk of a heart attack or stroke. [11] Higher HDL cholesterol levels reduce the risk of cardiovascular disease. 

Sorting out whether cholesterol intake correlates with blood cholesterol levels has been challenging.  Studies of the relationships between dietary cholesterol, blood cholesterol, and heart disease risk have had mixed results: a few show a positive correlation, but most do not.[12,13]  These differing results may be due in part to the fact that the ability to regulate blood cholesterol in response to changes in dietary cholesterol varies among individuals.[5] Also dietary components other than cholesterol can affect blood cholesterol levels. Of particular significance is saturated fat, which increases LDL cholesterol in the blood.[14] Foods high in cholesterol are usually also high in saturated fat or consumed alongside foods high in saturated fat, making it difficult to distinguish the effect of dietary cholesterol from that of saturated fat.[13] A review of currently available data concluded that there is not sufficient evidence to support an association between cholesterol intake and blood cholesterol levels or cardiovascular risk.[5]  In accordance with this conclusion, the American Heart Association now  suggests that rather than keeping cholesterol intake to a specific limit, we concentrate on consuming a healthy dietary pattern. [13] 

A Healthy Dietary Pattern 

A healthy dietary pattern emphasizes fruits, vegetables, and whole grains, which are high in fiber, and limits saturated fat, sodium, and added sugars. Eggs can be included in this pattern, but the number of eggs that is healthy for an individual depends on their genetics and health history. For example, healthy adults with no family history of heart disease, normal blood cholesterol levels, and no heart disease risk factors can consume up to 2 eggs per day as part of a heart-healthy dietary pattern. [13,15]. But individuals with heart disease risk factors such as high blood cholesterol, diabetes, obesity, or high blood pressure should be more cautious with their egg intake, limiting it to no more than 4 to 5 eggs per week [13,15].  

Whether you like your eggs poached, scrambled, fried, or boiled be careful of what you pair them with. A meal of eggs with sausage, bacon, buttery biscuits, or cheese is high in saturated fat and low in fiber so would have to be a rare treat. However, eggs scrambled with mushrooms, peppers, spinach, and tomatoes served with fresh berries and whole grain toast contains little saturated fat and plenty of fiber from fruits, vegetables, and whole grains so it fits easily into a healthy dietary pattern. 

Enjoy Some Eggs

Eggs are a convenient, relatively inexpensive, easily digestible source of high-quality protein. They provide a variety of vitamins, minerals, and carotenoids and have a lower environmental impact than most animal products.[16] Although they are high in cholesterol, they contain almost no saturated fat and so do not raise unhealthy LDL cholesterol levels. If you choose to include eggs as part of your healthy dietary pattern enjoy them within the context of your individual health history. 

References

[1] Keys A. Prediction and Possible Prevention of Coronary Disease. American Journal of Public Health and the Nations Health. 1953;43(11):1399-1407. doi:https://doi.org/10.2105/ajph.43.11.1399

[2] Menotti A, Puddu PE. Ancel Keys, the Mediterranean Diet, and the Seven Countries Study: A Review. Journal of Cardiovascular Development and Disease. 2025;12(4):141. doi:https://doi.org/10.3390/jcdd12040141

 [3] Carter S, Elizabeth Sanchia Connole, Hill AM, Buckley JD, Coates AM. Eggs and Cardiovascular Disease Risk: An Update of Recent Evidence. Current Atherosclerosis Reports. 2023;25(7):373-380. doi:https://doi.org/10.1007/s11883-023-01109-y

 [4]American Heart Association. New federal guidelines may lift dietary cholesterol limits. www.heart.org. Published November 13, 2017. https://www.heart.org/en/news/2018/07/18/new-federal-guidelines-may-lift-dietary-cholesterol-limits

[5] Fernandez ML, Murillo AG. Is There a Correlation between Dietary and Blood Cholesterol? Evidence from Epidemiological Data and Clinical Interventions. Nutrients. 2022;14(10):2168. doi:https://doi.org/10.3390/nu14102168

[6] Griffin BA. Eggs: good or bad? Proceedings of the Nutrition Society. 2016;75(3):259-264. doi:https://doi.org/10.1017/S0029665116000215

[7] Puglisi MJ, Fernandez ML. The Health Benefits of Egg Protein. Nutrients. 2022;14(14):2904. doi:https://doi.org/10.3390/nu14142904

[8] Keogh J, Clifton P. Energy Intake and Satiety Responses of Eggs for Breakfast in Overweight and Obese Adults—A Crossover Study. International Journal of Environmental Research and Public Health. 2020;17(15):5583. doi:https://doi.org/10.3390/ijerph17155583

[9] Zhou R, Yang M, Yue C, et al. Association between Dietary Choline Intake and Cardiovascular Diseases: National Health and Nutrition Examination Survey 2011–2016. Nutrients. 2023;15(18):4036. doi:https://doi.org/10.3390/nu15184036

[10] Jia YP, Sun L, Yu HS, et al. The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases. Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry. 2017;22(4). doi:https://doi.org/10.3390/molecules22040610

[11] Merschel M. Here’s the latest on dietary cholesterol and how it fits in with a healthy diet. www.heart.org. Published August 25, 2023. https://www.heart.org/en/news/2023/08/25/heres-the-latest-on-dietary-cholesterol-and-how-it-fits-in-with-a-healthy-diet

[12] Zhong VW, Van Horn L, Cornelis MC, et al. Associations of Dietary Cholesterol or Egg Consumption With Incident Cardiovascular Disease and Mortality. JAMA. 2019;321(11):1081. doi:https://doi.org/10.1001/jama.2019.1572

[13] Carson JAS, Lichtenstein AH, Anderson CAM, et al. Dietary Cholesterol and Cardiovascular Risk: A Science Advisory From the American Heart Association. Circulation. 2020;141(3):39-53. doi:https://doi.org/10.1161/cir.0000000000000743

[14] Flock, M. R., and Kris-Etherton, P. M. Diverse physiological effects of long-chain fatty acids: Implications for cardiovascular disease. Curr Opin Clin Nutr Metab Care 16:133–140, 2013.

[15] Gunnars K. Eggs and Cholesterol — How Many Eggs Can You Safely Eat? Healthline. Published August 23, 2018. https://www.healthline.com/nutrition/how-many-eggs-should-you-eat

[16] Myers M, Ruxton S. Eggs: Healthy or Risky? A Review of Evidence from High Quality Studies on Hen’s Eggs. Nutrients. 2023;15(12):2657-2657. doi:https://doi.org/10.3390/nu15122657